1. Field of the Invention
The present invention relates to a technique for projecting an image. Particularly, the invention relates to a device and a method for projecting an image with laser light.
2. Description of the Background Art
Projectors that project an image onto a projection target plane such as a wall are presently used in many places. In recent years, various kinds of projectors have been under development.
An imaginary keyboard is one of uses of the projector. For example, National Publication No. 2004-523031 has disclosed a data input device that can be used as an imaginary keyboard. This data input device includes an illumination device emitting light to an engagement plane, a sensor sensing the light that is emitted by the illumination device and is scattered by engagement of an object with an engagement plane, and a processor receiving an output of the sensor and providing data entry input to a service circuit.
Japanese Patent Laying-Open No. 2005-38422 has disclosed a projector. This projector displays an imaginary keyboard image on a first plane, and displays a user-output display image on a second plane. A lower portion of the imaginary keyboard is overlaid on a keystroke sensing system.
Japanese Patent Laying-Open No. 2000-305706 has disclosed a data input device. This data input device determines data input by sensing an obstruction that temporarily appears in an input area located outside a body of the device. This data input device uses a laser diode and diffraction optics for projecting an picture of a virtual keyboard onto the input area. The data input device uses an infrared transmitting device and an infrared receiving device for sensing a pointer or a finger located on the virtual keyboard.
Japanese Patent Laying-Open No. 2006-295779 has disclosed a portable information device. This portable information device includes a first casing and a second casing openably connected to the first casing. The first casing has a projection-type input display device for projecting the imaginary keyboard onto an input display area, a projection-type display device for projecting character data and image data onto a display area, and an input determining device for sensing an obstruction appearing in the input display area. An open/close angle between the first and second casings is variable. The input display area and the display area of the portable information device can be variably set by changing the open/close angle.
For accepting the user's operation, such a technique has been known that combines a touch panel with a screen displaying an image. For example, a projector device disclosed in Japanese Patent Laying-Open No. 2007-108570 projects a part of light emitted thereby to a slave screen near the projector device. The slave screen includes a screen and a touch panel superimposed on the screen. The projector device transmits a user's operation performed on the slave screen to a PC (Personal Computer) or the like.
The combination of the touch panel and the display screen disclosed in Japanese Patent Laying-Open No. 2007-108570 is also used in devices other than the projector. For example, a display processing device disclosed in Japanese Patent Laying-Open No. 2008-070968 moves, rotates, enlarges or reduces a displayed image based on positional information about two fingers touching the touch panel.
A navigation device disclosed in Japanese Patent Laying-Open No. 2003-344059 senses, through a touch panel, continuous input operations performed on at least two points on a navigation screen displaying a map. Also, the navigation device determines an operation direction of the input operation, and changes a scale of the map according to the operation direction.